The LED of the solid light-emitting element, owing to such electrical and optical advantages as low energy consumption, long service life, good stability, small size, fast response and stable light-emitting wave length, is widely applied in fields like illumination, household appliance, display and indicator. Moreover, this kind of light-emitting element enjoys considerable progress in light-emitting effect and service life and therefore, is promising to become the mainstream for a new generation of lighting and light-emitting element.
For traditional LED, a transformer is required during power supply to LED since it is driven by direct current (DC) while the general power supply is alternating current (AC), which not only increases the usage cost but also impedes the application of LED that is not originally intended for energy saving, due to electric energy loss during DC-AC transformation. In contrast, the AC LED, through DC-AC transformation, is available for usage as long as the general electric supply voltage is reduced. Without a transformer, the AC LED is more competitive than the traditional illuminants for it saves cost and space.
In general, the AC-LED often retains the original growth substrate and forms a vertical AC-LED by going through a complex process either by a) horizontally leading an interconnected lateral AC LED or b) by die pasting and flip-chip bonding after a single chip is completed.